I think 4 most likely because if u take the middle of the 3 dots it would lave the last dot on the 4
Population = 135 students
Mean score = 72.3
Standard deviation of the scores = 6.5
Part (a): Students from 2SD and 3SD above the mean
2SD below and above the mean includes 95% of the population while 3SD includes 99.7% of the population.
95% of population = 0.95*135 ≈ 129 students
99.7% of population = 0.997*135 ≈ 135 students
Therefore, number of students from 2SD to 3SD above and below the bean = 135 - 129 = 6 students.
In this regard, Students between 2SD and 3SD above the mean = 6/2 = 3 students
Part (b): Students who scored between 65.8 and 72.3
The first step is to calculate Z values
That is,
Z = (mean-X)/SD
Z at 65.8 = (72.3-65.8)/6.5 = 1
Z at 72.3 = (72.3-72.3)/6.5 = 0
Second step is to find the percentages at the Z values from Z table.
That is,
Percentage of population at Z(65.8) = 0.8413 = 84.13%
Percentage of population at (Z(72.3) = 0.5 = 50%
Third step is to calculate number of students at each percentage.
That is,
At 84.13%, number of students = 0.8413*135 ≈ 114
At 50%, number of students = 0.5*135 ≈ 68
Therefore, students who scored between 65.8 and 72.3 = 114-68 = 46 students
Answer:
x equal four-teen... I'm pretty sure brainliest plsss
Answer:
x = 1
y = -2
Explanation:
First, solve for x by subtracting 7y from both sides of the first equation and then divide both sides by -5.
-5x + 7y = -19
-5x + 7y - 7y = -19 - 7y
-5x = -19 - 7y
-5x/ -5 = -19 - 7y/ -5
x = -19 - 7y/ -5
Next, substitute the value of x into the second equation and solve.
6 - (-19 - 7y)/ 5 - 2y = 10
- 6(-19 - 7y)/ 5 - 2y = 10
Then, solve for y
- 6(-19 - 7y)/ 5 - 2y = 10
-6(-19 - 7y) - 10y = 50
114 + 42y - 10y = 50
144 + 32y = 50
32y = 50 - 144
32y = -64
32y/ 32 = -64/ 32
y = -2
Finally, substitute the value of y into the x value we found earlier and solve
x = - 19 - 7y/ 5
x = - 19 - 7 • -2/ 5
x = 1
Answer:
Question 2:
If the size of bacteria is 2000 initially and doubles after every half hour
It means in the 1st 30 min its size is 2000
And in 60 min its
30min=2000
60min=?
60×2000=120000
120000÷30
=4000
And in 9hrs
1hr=60min
9hrs=?
60×9=540min
30min=2000
540min=?
2000×540
=1080000÷30
=360000
